From the point of view of the invention not only the vehicles driven by motors fed from a current collector or a primary electrical source (e.g. galvanic elements, thermoelements, storage batteries and fuel cells) are to be considered as electrical vehicles, but all vehicles with an electrical power transmission belong to this group: Diesel-electric vehicles are characteristic of this latter class.
Several systems are known, where exploitation of electrical machines has been increased by the use of a gaseous cooling media (DT No. 2 063 229); turbogenerators cooled by hydrogen under pressure (of several atmospheres) have been widely used. In these systems, however, the traditional structures for insulation of the armature windings and formation of the armature windings and formation of the armature winding heads have been maintained, restructing the possibility of complete exploitation of the increased cooling effect of the gas under pressure.